Several new michellamine-related alkaloids have been isolated from extracts of Ancistrocliadus korupensis; purification and complete structure elucidation of these and other related components are continuing. Purification and characterization of active components from the antitumor extract of the sponge Cribochalina vasculum have yielded two enynols demonstrating high selectivity toward a single non-small cell lung tumor line. Further in vivo evaluations of these compounds are being conducted. Isolation, purification and characterization of active constituents from several other antitumor leads of sponge origin, Esperiopsis sp., Raspailia sp., Zyzzya sp. and Inflatella sp. are being pursued.